Methods and apparatus for geo-collaboration

ABSTRACT

Methods and computer readable medium for collaborating on geographical maps between two or more computers are disclosed. In particular, sharing a geographical location on a map between two or more computers and co-navigating a map between two or more computers are disclosed. With respect to sharing a geographical location, the geographical location is retrieved to the first computer. The geographical location is added to the map being rendered at the first computer and is sent to a second computer. A map including the geographical location is rendered at the second computer. With respect to co-navigating, a map is displayed from a map perspective at the first computer. The map perspective is sent to the second computer. A map from the same map perspective being displayed at the first computer is rendered at the second computer.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/636,953 filed on Dec. 17, 2004 entitled “Geo-CollaborationSystem”, which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to methods and apparatus forcollaborative usage of geographical information, and more particularly,to advantageous techniques for combining geographical informationsystems with collaborative systems to achieve advantageous map featuresbetween users of two or more computers.

BACKGROUND OF THE INVENTION

Geographical information systems (GIS), computerized mapping systemsthat enable a user to visualize geographical information such astopographical, natural or man made borders, rivers, lakes, and the likehave been around for many years. A computerized map file, such asEnvironmental Systems Research Institute's (ESRI) geodatabase fileformat, comprises one or more layers of geographical information which,when rendered together on a computer screen, shows a user a cognizablemap. Each layer may provide different information relating to geographyor contain geospatial information such as statistical, demographic, andother like information relating to the geography. For example, a worldmap may have five or more layers. One layer may include geographicalinformation to render the borders of the world's continents. A secondlayer may include geographical information to render the borders of theworld's countries. A third layer may include geographical information torender the borders of states in a country. A fourth layer may includegeographical information to render the borders of counties in a state. Afifth layer may include geographical information to render the bordersof cities within the counties. Other layers may include populationdistributions, school districts, locations of government offices, andthe like.

Collaborative software is application software that integrates work on asingle project by several concurrent users at separated workstations. Inits modern form, it was pioneered by Lotus Software with the popularLotus Notes application running in connection with a Lotus Dominoserver. Collaborative software allow participants to have collaborativeinteractions which allow participants to alter a collaboration entitysuch as a document or other common deliverable. Typically, collaborativesoftware applications are limited to allowing users to jointly edit adocument, a presentation, a spreadsheet, or other flat file.Collaborative software applications may provide a virtual repositorywhich allows data to be replicated, stored, and synchronized on multiplecomputers operating in a peer-to-peer relationship. A member of avirtual repository is a user who has been assigned and given permissionto share information in the virtual repository. For example, Groove®Virtual Office provides a concept called a “workspace“ which allowsusers, who have been assigned to the same workspace, to share andsynchronize files which have been added to the workspace.

Computerized maps, on the other hand, may contain voluminous and complexinformation. Rather than merely revealing magnified information whenzooming in on documents, presentations, spreadsheets, when a user zoomsin on a computerized map, additional information is revealed to theuser. For example, a user viewing the map of the United States may seethe borders of each state and the country's borders. However, when theuser zooms into a particular city street, the viewer may render pointsof interest to the user such as particular stores, gas stations, parks,and the like. Additionally, a user may scroll a map, for example of theworld, which has no defined beginning or end. Consequently, a map filehas to contain a lot of information that may or may not be rendereddepending on a user's interaction with a map.

As noted in “IT Roadmap to a GeoSpatial Future,“ The National AcademiesPress, 2003, many problems in combining GIS with collaborative softwareapplications have been identified. This book recognizes that “there hasbeen no attention to how the new collaborative features might beintegrated with geospatial analysis activities and only limitedattention to the role of interactive visualizations in facilitatingcooperative work.“ Furthermore, this work recognizes that the volume andcomplexity of the geospatial information will make it increasingly hardto use effectively. This book recognizes that many research efforts havecentered on the creation of virtual spaces but have not determined howto enable navigation through virtual spaces in a collaborative manner.

SUMMARY OF THE DISCLOSURE

Among its several aspects, the present invention addresses problems suchas those described above and brings together the core functions ofcollaborative software applications with those of GIS to provide acollaborative framework based on maps and location. Another aspect ofthe present invention provides computer users with the ability to share,independently of their respective location, maps and geospatialinformation overlaid on maps. Another aspect of the present invention,called decentralized data updating in synchronous and asynchronousmodes, provides users with the ability to work with geospatialinformation while connected or disconnected from other collaborators.Another aspect of the present invention, called asymmetrical informationmanagement, provides users with the ability to choose to share all orportions of their own geospatial information with other users.

Methods and computer readable medium for collaborating on geographicalmaps between two or more computers are disclosed. In particular,techniques for sharing a geographical location on a map between two ormore computers and co-navigating a map between two or more computers aredisclosed. As an example, with respect to sharing a geographicallocation, the geographical location is retrieved to the first computer.The geographical location is added to the map being rendered at thefirst computer and is sent to a second computer. A map including thegeographical location is rendered at the second computer. As anotherexample, with respect to co-navigating, a map is displayed from a mapperspective at the first computer. The map perspective is sent to thesecond computer. A map from the same map perspective being displayed atthe first computer is rendered at the second computer.

A more complete understanding of the present invention, as well asfurther features and advantages of the invention, will be apparent fromthe following Detailed Description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an illustrative system employing a geo-collaboration systemin a stand alone environment in accordance with the present invention.

FIG. 2 shows an illustrative network environment employinggeo-collaboration system in accordance with the present invention.

FIG. 3A shows an exemplary main screen for geo-collaboration software inaccordance with the present invention.

FIG. 3B shows a map of New Orleans, La. being rendered bygeo-collaboration software at computer 112A in accordance with thepresent invention.

FIG. 3C shows a map of Slidell, La. being rendered by thegeo-collaboration software at computer 112B in accordance with thepresent invention.

FIG. 3D shows a map of New Orleans and Slidell being rendered by thegeo-collaboration software at computer 112C in accordance with thepresent invention.

FIG. 3E shows a view perspective of a map of New Orleans and Slidellbeing rendered by the geo-collaboration software at computer 112C beforeacting as a leader in accordance with the present invention.

FIG. 3F shows a view perspective of a map of New Orleans, La. beingrendered by the geo-collaboration software at computer 112A beforeacting as a follower in accordance with the present invention.

FIG. 3G shows a view perspective of a map of Slidell, La. being renderedby the geo-collaboration software at computer 112B before acting as afollower in accordance with the present invention.

FIG. 3H shows a view perspective of a map of New Orleans' and Slidellbeing rendered by the geo-collaboration software at computer 112C whileacting as a leader in accordance with the present invention.

FIG. 3I shows a view perspective of a map of New Orleans, La. beingrendered by the geo-collaboration software at computer 112A while actingas a follower in accordance with the present invention.

FIG. 3J shows a view perspective of a map of Slidell, La. being renderedby the geo-collaboration software at computer 112B while acting as afollower in accordance with the present invention.

FIG. 3K shows a pop-up screen for plotting and sharing an iconcorresponding to an inputted address on to a map in accordance with thepresent invention.

FIG. 3L shows a map with a plotted icon according to the inputtedaddress of FIG. 3K.

FIG. 4 shows a block diagram of a portion of geo-collaboration softwarewhich addresses layer management and map item management betweencomputers in accordance with the present invention.

FIG. 5 shows a calling sequence illustrating the interactions of thesoftware class instances of FIG. 4 for adding and removing map layers.

FIG. 6 shows a calling sequence illustrating the interaction of thesoftware objects of FIG. 4 for adding items to a map.

FIG. 7 shows a block diagram of a portion of geo-collaboration softwarewhich addresses co-navigating a map shared between two or more computersin accordance with the present invention.

FIG. 8 shows a calling sequence illustrating the interactions of thesoftware class instances of FIG. 7 for co-navigating a map.

FIG. 9 shows a block diagram of a portion of geo-collaboration softwarewhich addresses location awareness on a map shared between two or morecomputers in accordance with the present invention.

FIG. 10 shows a calling sequence illustrating the interactions of thesoftware class instances of FIG. 9 for sharing a location retrieved froma GPS system of a person or item on a map shared between two or morecomputers.

FIG. 11 is a flow chart of a method for synchronizing map layers betweentwo or more computers according to the present invention.

FIG. 12 is a flow chart of a method for sharing a map item between twoor more computers according to the present invention.

FIG. 13 is a flow chart of a method for co-navigating a map shared bytwo or more computers according to the present invention.

FIG. 14 is a flow chart of a method for plotting and sharing thelocation of a member between two or more other members of a commonvirtual repository in accordance with the present invention.

DETAILED DESCRIPTION

The present invention will now be described more fully with reference tothe accompanying drawings, in which several presently preferredembodiments of the invention are shown. This invention may, however, beembodied in various forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

As will be appreciated by one of skill in the art, the present inventionmay be embodied as methods, systems, or computer program products.Accordingly, the present invention may take the form of a hardwareembodiment, a software embodiment or an embodiment combining softwareand hardware aspects. Furthermore, the present invention may take theform of a computer program product on a computer-usable storage mediumhaving computer-usable program code embodied in the medium. Any suitablecomputer readable medium may be utilized including hard disks, CD-ROMs,optical storage devices, flash memories, or magnetic storage devices.

FIG. 1 shows a diagram of a system 100 employing a geo-collaborationsystem in a stand-alone environment accordance with the presentinvention. The illustrated system 100 is implemented as a stand-alonepersonal computer or workstation 112. As described in further detailbelow, system 100 includes geo-collaboration software 130 in accordancewith the present invention which is stored in memory and run by thecentral processing unit of the personal computer 112. The presentlypreferred geo-collaboration software 130 is embodied in a softwareproduct known as Toucan Navigate. System 100 also includes collaborationsoftware 140 such as Groove® Virtual Office which is also stored inmemory and run by the central processing unit of the personal computer112. The collaboration software 140 is responsible for synchronizingdata on a peer-to-peer basis between two or more computers. For example,if a document is shared between two computers, each computer has a copyof the document and the collaboration software is responsible forsynchronizing the latest updates to the document to each respectivecopy. Although the present invention has been implemented using Groove®Virtual Office, it should be noted that the use of other collaborationsoftware applications which can synchronize data between two or morecomputers is contemplated by the present invention.

The computer 112 includes a number of standard input and output devices,including a keyboard 114, mouse 116, CD-ROM drive 118, disk drive 120,and monitor 122. In addition, the computer 112 includes an Internet ornetwork connection 126 for downloading software, data, and updates. Itwill be appreciated, in light of the present description of theinvention, that the present invention may be practiced in any of anumber of different computing environments without departing from thescope of the invention. For example, the system 100 may be implementedin a network configuration with individual workstations connected to aserver. Also, other input and output devices such as laptops, handhelddevices, or cell phones, for example, may be used, as desired.

One embodiment of the invention has been designed for use on astand-alone personal computer, laptop, or workstation on an IntelPentium or later processor, using as an operating system Windows XP,Windows NT, or the like.

In the configuration depicted in FIG. 1, the geo-collaboration software130 in accordance with the present invention may be used to add andremove layers of a map, to add and remove geographical objects to alayer or layers, and to add and remove a location to a map. Thesefunctions are described in further detail in connection with FIGS. 4-6.A layer may be static or dynamic. A static layer contains well-knowngeography such as roads, county borders, all the locations of McDonaldsin Texas, and the like. A dynamic layer contains map objects which arecreated in response to information coming from a remote data source oradded by an individual user. One remote data source, for example, is theNational Office of Aeronautics which provides a severe weather warningfeed of information. Geographical objects may be added to a static ordynamic layer. Exemplary geographical objects include a point, a line, a2-dimensional shape, a 3-dimensional shape, a graphic, and the like.

FIG. 2 shows an illustrative network environment 200 employinggeo-collaboration system in accordance with the present invention. Thenetwork environment 200 includes three computers 112A-112C and a network220. The network 220 may include any local area network, wide areanetwork, Internet, some combination of network connections, or the like.The network environment 200 may suitably include wired and wirelessconnections. Computers 112A-112C operate in a peer-to-peer relationship.Computers 112A-112C execute geo-collaboration software 130 in accordancewith the present invention and collaboration software application 140.Although FIG. 2 shows three computers 112A-112C, geo-collaborationfeatures involving the sharing of geo-spatial information achieved bygeo-collaboration software 130 according to the teachings of the presentinvention may include two or more computers.

If, for example, a map or a layer of a map is modified on computer 112Awhile in the stand alone environment as illustrated in FIG. 1, all ofthe modifications to the map and layer which are shared with other usersare synchronized once computer 112A is connected to network 220. Whilecomputers 112A-112C are connected over a network and modifications aremade to a map or a layer of a map, a modification made on computer 112Abecomes viewable on computers 112B and 112C and vice versa as long asthe map or layer of the map containing the modification is sharedbetween the computers. Further exemplary details of how modificationsare shared will be described in connection with FIGS. 4 and 5.

FIG. 3A shows the main user interface screen 300 of thegeo-collaboration software 130 in accordance with the present invention.The main screen 300 includes a map viewer 310. The map viewer 310includes a map toolbar 320, a map item pane 340, a layers pane 350, aco-navigate pane 360, and a team location pane 370. Each of these panesprovides access to geo-collaboration features implemented bygeo-collaboration software 130. As shown in FIG. 3A, the map viewer 310renders an exemplary map 330 of the Earth. It should be noted that theshading shown in FIGS. 3A-3L represent various colors displayed on acomputer screen.

The map item pane 340 displays the current location of pointing deviceor cursor 347 on the rendered map 330. As shown, the map item pane 340displays that the present cursor 347 is at rest at longitude −86.027523°and the latitude is 39.291227°. The map item pane 340 may also displayattributes associated with a particular location being pointed to by apointing device, interacting with a global positioning system (GPS)device, or the like. For example, if the pointing device points to alocation which has been assigned other attributes like an address, atelephone number, names, or the like, those attributes would also bedisplayed in the map item pane 340.

The layers pane 350 provides a user the capability to manage layers thatcompose the rendered map 330. The map viewer 310 aggregates and rendersall the loaded layers of a map as indicated in the layers pane 350. Asillustrated in FIG. 3, the map view 310 renders layers named “countries“and “incidents“ to compose the map 330. A map layer may comprise coloredsymbols, labels, shapes defined by one or more persons which arereplicated to other related computers. To add a layer, the user clickson link 351. A layer may be added from the file system accessible by theprocessor executing the geo-collaboration software application 130 or ashared virtual repository such as a workspace. The added layer is thenrendered by the map viewer 310 and overlaid on map 330. If, for example,the map viewer 310 was being executed by computer 112A and that thelayer was retrieved from computer 112A's file system, the added layerwould only be visible on computer 112A. On the other hand, if the layerwas retrieved from the shared virtual repository and the users ofcomputers 112B and 112C were also members of the shared virtualrepository, the map viewers executing on computers 112B and 112C woulddisplay the layer added by computer 112A. This feature of managinglayers of a map is called decentralized geographical data update becauseany member may add a layer of a map to be shared or not depending onwhether the layer has been added to the shared virtual repository.

Toolbar 320 provides tools including a tool for managing a layer. The“Add“ drop down provides a user to add incidents such as points, lines,areas, and other objects to a layer of map 330. For example, if the userat computer 112A adds a new layer as described in further detail inconnection with FIG. 5, the user can add incidents to the map layer andif the map layer is taken from or added to a shared virtual repository,those added incidents are then rendered by map viewers executing oncomputers 112B and 112C.

Exemplary geo-collaboration features include asymmetric geographicalinformation management, co-navigation, team location presence andawareness, and decentralized geographical data updates. The asymmetricgeographical information management, co-navigation, and team locationpresence and awareness features will be discussed further below in orderby showing a visible representation of the features. A discussion of theinternal software components of the geo-collaboration softwareapplication 130 to achieve the features will then follow.

FIGS. 3B-3D show portions of maps being shared between users atcomputers 112A-112C respectively to illustrate the feature entitledgeo-visualization. The user of computer 112A is a member of a virtualrepository called “New Orleans Power Outage.“ The user of computer 112Bis a member of a virtual repository called “Slidell Power Outage.“ Theuser of computer 112C is a member of both virtual repositories. Forexample, the user of computer 112A may be a relief manager responsiblefor New Orleans, the user of computer 112B may be a relief managerresponsible for Slidell, and the user of computer 112C may be themanager responsible for the entire state of Louisiana.

FIG. 3B shows a map 311 of New Orleans, La. being rendered by thegeo-collaboration software 130 at computer 112A in accordance with thepresent invention. As a member of the New Orleans Power Outage virtualrepository, the map viewer 310 renders a certain set of map layers.Referring to layer pane 312, these rendered layers include Power Off—NewOrleans, Incidents, highways, state capitals, states, lakes, rivers, andLouisiana roads. How these layers are added to other computers, edited,and removed in order to be presented across multiple computers will bedescribed in further detail in connection with discussion of FIG. 5. ThePower Off—New Orleans layer is illustrated by the display icons313A-313C which represents locations in New Orleans where the power isoff. Map item pane 314 displays information related to the power offlocation map item 313C. This information is displayed when a pointingdevice hovers or clicks on an icon of interest. Adding, updating, anddeleting map item information according to the present invention acrossmultiple machines is discussed in further detail in connection with FIG.6. A map item when rendered in a map may be a location, a point, a line,a shape, an icon, or the like.

FIG. 3C shows a map 321 of Slidell, La. being rendered by thegeo-collaboration software 130 at computer 112B in accordance with thepresent invention. As a member of the Slidell Power Outage virtualrepository, the map viewer 310 renders a certain set of map layers.Referring to layer pane 322, these rendered layers include PowerOff—Slidell, incidents, highways, state capitals, states, lakes, rivers,and Louisiana roads. The Power Off—Slidell layer is illustrated by thedisplay icons 323A-323C which represents locations in Slidell where thepower is off. Since a pointing device 325 is over location 323C, mapitem 324 displays information related to the power off status atlocation 323C. Since the relief manager responsible for Slidell, whouses the computer 112B, is not a member of the virtual repository “PowerOutages—New Orleans,“ the power outages in New Orleans are not shown oncomputer 112B. Likewise, referring to FIG. 3B, since the relief managerresponsible for New Orleans, who uses the computer 112A, is not a memberof the virtual repository “Power Outages—Slidell,“ the power outages inSlidell are not shown on the computer 112A.

FIG. 3D shows a map 331 of New Orleans and Slidell being rendered by thegeo-collaboration software 130 at computer 112C in accordance with thepresent invention. As a member of both the Slidell Power Outage and theNew Orleans virtual repositories, the layer pane 332 contains both thePower off—Slidell and Power Off—New Orleans layers. As a result, the mapviewer 330 renders icons 313A-313C which represent locations in NewOrleans where the power is off and icons 323A-323C which representlocations in Slidell where the power is off. The utility managerresponsible for the entire state of Louisiana utilizing computer 112Chas view or map perspective of power outages commensurate with his orher area of responsibility.

It should be noted that the map viewers at computers 112A and 112B donot render map layers associated with a virtual repository to which auser is not a member. This asymmetric geographical informationmanagement feature allows geo-spatial information to be shared on an asneeded basis. Since the manager responsible for the entire state ofLouisiana, for example, has access to both the power outage layers, themanager may add additional points of interest to either of these layerssuch as other power outages, the location of service personnel, and thelike. Once these additional points of interest are added to the layers,geo-collaboration software 130 being executed on computers 112A and 112Bwill render these additional points in the maps on computers 112A and112B.

If all the computers are communicating over the network at the time,additional points of interest are added, the additional points ofinterest will be automatically rendered at substantially the same timeat all the computers. The idea of substantially the same time as usedherein includes any delays in transmitting information through anetwork. If, for example, computer 112A was not communicating with thenetwork 220 at the time the manager added the additional points ofinterest, computer 112A will render the additional points of interestonce the computer 112A communicates over the network 220. If, forexample, the manager added the additional points of interest whilecomputer 112C was not communicating with the network 220, the additionalpoints of interest will be rendered at computers 112A and 112B aftercomputer 112C begins communicating with network 220. How thegeo-collaboration software 130 provides updates between computers isaddressed further in connection with the discussion of FIG. 5.

FIGS. 3E-3J illustrate the co-navigation feature of geo-collaborationsoftware 130 in accordance with the present invention. Co-navigationprovides users of a shared virtual repository located at variouslocations to have the same view perspective of a map as one of theusers, called the leader. The leader establishes the view perspectiveand shares that view perspective with the other users of the virtualrepository, called followers. FIGS. 3E-3G are map perspectives beingautomatically rendered at substantially the same time at computers 112C,112A, and 112B, respectively, before the co-navigation feature isinvoked. FIGS. 3H-3J are map perspectives being automatically renderedat substantially the same time at computers 112C (leader), 112A (firstfollower), and 112B (second follower), respectively, while theco-navigation feature is invoked.

FIG. 3E shows a view perspective 353 of a map of New Orleans and Slidellbeing rendered by the geo-collaboration software at computer 112C beforethat computer begins acting as a leader in accordance with the presentinvention. The view perspective 353 includes an altitude indicator 352indicating that view perspective 353 is from an altitude of 78 milesabove sea level. Referring to the Co-Navigate pane 360, the user atcomputer 112C is informed that he or she is not participating in aco-navigation session by the “neither“ button being selected.

FIG. 3F shows a view perspective 354 of a map of New Orleans, La. beingrendered by the geo-collaboration software 130 at computer 112A beforethat computer begins acting as a follower in accordance with the presentinvention. The view perspective 354 includes an altitude indicator 355indicating that view perspective 354 is from an altitude of 20 milesabove sea level.

FIG. 3G shows a view perspective 356 of a map of Slidell, La. beingrendered by the geo-collaboration software 130 at computer 112B beforethat computer begins acting as a follower in accordance with the presentinvention. The view perspective 356 includes an altitude indicator 357indicating that view perspective 356 is from an altitude of 10 milesabove sea level.

FIGS. 3H-3J are map perspectives being automatically rendered atsubstantially the same time at computers 112C, 112A, and 112B,respectively, while the co-navigation feature is invoked.

FIG. 3H shows a view perspective 358 of a map of New Orleans and Slidellbeing rendered by the geo-collaboration software 130 at computer 112Cwhile acting as a leader in accordance with the present invention. Theuser of computer 112C has invoked the co-navigation feature by selectingthe lead button 341. While viewing FIG. 3E, the user of computer 112Chas zoomed in to a bridge accident. Indicator 359 indicates that theview perspective 358 is from an altitude of 34 miles. For purposes ofthis example, it is assumed users at computers 112A and 112B have joinedthe co-navigation session.

FIG. 3I shows a view perspective 342 of a map of New Orleans, La. beingrendered by the geo-collaboration software 130 at computer 112A whileacting as a follower in accordance with the present invention. Thefollow button 343 selection indicates that the user of computer 112A hasrequested and has now joined the co-navigation session with computer112C. View perspective 342 has an altitude indicator 344 indicating thatthe view perspective 342 is from an altitude of 34 miles, equivalent toview perspective 358. While in the co-navigation session, wherever theuser of computer 112C moves his or her map perspective, the user ofcomputer 112A will automatically view his or her map from the same mapperspective being viewed at computer 112C.

It should be noted that since the user of computer 112A is a member ofNew Orleans Power Outage virtual repository sees only the map layersassociated with the New Orleans Power Outage virtual repository such asthe power outages in New Orleans. The New Orleans Power Outage virtualrepository contains the layer incidents 345 which include the map item346 indicting a bridge accident. Consequently, the user of computer 112Amay view the bridge accident 347 in view perspective 342.

FIG. 3J shows a view perspective 348 of a map of Slidell, La. beingrendered by the geo-collaboration software 130 at computer 112B whileacting as a follower in accordance with the present invention. Theselection of follow button 333 indicates that the user of computer 112Bhas also joined the co-navigation session with computers 112A and 112Cas a follower. Like the user of computer 112A, whenever the user ofcomputer 112C changes his or her view perspective, geo-collaborationsoftware 130 of computer 112B renders his or her map from the same viewperspective of computer 112C. Consequently, view perspective 348contains an altitude indicator 349 indicating that the view perspectiveis from an altitude of 34 miles, the same view perspective of FIG. 3Hrendered at computer 112C. Since the user of computer 112B is a memberof the Slidell Power Outage virtual repository, he or she only seespower outages in Slidell and does not see the power outages in NewOrleans. However, since the incidents layer 345 is shared in both theSlidell Power Outage virtual repository and the New Orleans Power Outagevirtual repository, the bridge accident is also rendered in viewperspective 348. Further detail of how co-navigation is achieved isaddressed in connection with the discussion of FIGS. 7 and 8.

The geo-collaboration software 130 supports various techniques forplotting and sharing the location of a user to a map. For example, auser of geo-collaboration software 130 may click with a pointing deviceon a map, may input a specific address, or may specify a particularvCard to indicate his or her location. A vCard is an Internet standardfor creating and sharing virtual business cards. Additionally,geo-collaboration software 130 may interface to a global positioningsystem (GPS) and plot the corresponding GPS coordinates onto a sharedmap.

FIG. 3K shows a pop-up screen 334 for plotting and sharing an iconcorresponding to an inputted address in accordance with the presentinvention. After a user of geo-collaboration software 130 inputs anaddress into the pop-up screen 334 and clicks the Find button, thegeo-collaboration software 130 retrieves geographical coordinatescorresponding to the address and plots an icon onto a map according tothe retrieved geographical coordinates. For example, the user ofcomputer 112C may be wirelessly connected to network 220 and located ina utility truck 104. The user would input his or her current Slidelladdress into pop-up screen 334 and would click the Find button.

FIG. 3L shows a map 335 with a plotted icon 336 according to theinputted address of FIG. 3K. Since the user of computer 112C is a memberof both the New Orleans Power Outage and the Slidell Power Outagevirtual repositories, the plotted icon 336 will be rendered bygeo-collaboration software 130 running on computers 112A and 112B and,thus, shared with users of computers 112A and 112B. It should be notedthat the icon of truck 206 of map 335 has had its location plotted frominterfacing with a GPS. Further detail of how this location awarenessfeature is achieved is addressed in connection with the discussion ofFIGS. 9 and 10.

FIG. 4 shows a block diagram 400 of a portion of geo-collaborationsoftware which performs layer management and map item management betweencomputers in accordance with the present invention. The block diagram400 shows software classes 410-470 which, when instantiated, interactwhich each other to accomplish decentralized geographical data updates.The user interface class 410 is responsible for showing the currentstate of the geo-collaboration software application 130 to the user andacting as a means with which the user can modify map data and maplayers. The map controller class 420 is responsible for coordinating theother class instances that make up the geo-collaboration softwareapplication 130.

LayerStore class 430 encapsulates any persistent storage such as a harddrive, file directory, web service, or database used to map data.MapItem class 460 represents a point, lines including roads, shapes, andother data constructs with a geographic element such as observations orlocation reports. MapLayer class 470 may contain one or more MapItemsthat share a common set of characteristics such as display properties.Map class 440 is responsible for the display of MapItem class instancesand MapLayer class instances. PropertyReplicator class 450 isresponsible for asynchronously disseminating the definitions of MapItemand MapLayer instances to other computers executing geo-collaborationsoftware 130. The definitions of MapItems and MapLayers may be encodedin extended markup language (XML), binary objects, serial objects, orany other suitable format. The operations of these classes will befurther described in connection with FIGS. 5 and 6. It should be notedthat in this context the terms class instance or object mean aninstantiation in memory of a corresponding class during run time of thegeo-collaboration software 130.

FIG. 5 shows a calling sequence 500 illustrating the interactions of thesoftware class instances of FIG. 4 for adding and removing map layers inthe geo-collaboration software 130. In the calling sequence, the methodcalls 510, 520, 530, 540, 550, 560, 570, 580, and 590 are executed by acomputer, such as computer 112A running geo-collaboration software 130.Method calls 512 and 522 are executed by computer 112A and any othercomputers such as computers 112B and 112C running geo-collaborationsoftware 130 whose users are members of the same virtual repository.

A user of geo-collaboration software 130 executing on computer 112Awanting to share a map layer containing his or her favorite bicycletraining routes through the city with users at computers 112B and 112Cis an example of when the sequence of method calls 510, 520, 530, 540,550, 560, 570, 580, and 590 are executed. Or, as described above, themanager responsible for addressing power outages in the state ofLouisiana may want to report locations of utility service personnel toother coworkers. To add the map layer to a map, a user selects the “Add“pull down menu accessible from toolbar 320. Upon clicking on the addfeature, the AddMapLayer( ) method 510 on the User Interface class 410is called. AddMapLayer( ) method 510 then calls AddMapLayer( ) method520 on the Map Controller class 420. The AddMapLayer( ) method 520 callsthe LocateMapLayers( ) method 530 on the LayerStore class 430 andretrieves map layers accessible through the repository encapsulated bythe LayerStore class 430. The PresentMapLayerSelection( ) method 535returns the retrieved map layers and their associated metadata includingtheir position to the user.

Upon retrieving the map layers, these selectable layers may be presentedthrough the layers pane 350. The user selects one or more map layers tobe added to the shared map and, thus, to be aggregated by the map viewer310. The SelectLayers( ) method 540 is called on the User Interfaceclass 410. The SelectLayers( ) method 540 calls the SelectLayers( )method 550 on the Map Controller class 420. The SelectLayers( ) method550 calls the RetrieveLayer( ) method 560 on the LayerStore class 430,the AddLayer( ) method 570 on the Map class 440 and theSetLayerMetaData( ) method 580 on the PropertyReplicator class 450. TheRetrieveLayer( ) method 560 retrieves the selected layer from theLayerStore 430, saves the selected layer and associated metadata andconfiguration and data files to the local computer 112A.

Metadata for a layer describes characteristics of the layer such as thelayer's name, whether it is visible, what display styles it contains,and the like. An exemplary layer style may include information to renderall point map objects on a layer with the true type font symbol for anairport using red 22 point type.

The AddLayer( ) method 570 adds the selected layer and the associatedmetadata and configuration and data files to the Map class instance 430.In so doing, the create( ) method 575 creates a new map layer andreturns the select layer's XML or other binary or serial representationof the layer to the MapLayer class 470. The LayerMetaDataXML( ) method577 returns the selected layer's XML to the Map Controller class 420which in turn returns the selected layer's XML to the User Interfaceclass 410 at time 579.

The Map Controller class 420 then calls the SetLayerMetaData( ) method580 on the PropertyReplicator class 450. The SetLayerMetaData( ) method580 updates the PropertyReplicator class 450 with the selected layer'sXML data and disseminates the selected layer's XML data to other membersrunning the geo-collaboration software 130. Although not shown insequence diagram 500, the PropertyReplicator class 450 interfaces withcollaboration software 140 in order for collaboration software 140 tosynchronize information such as the selected layer's XML data betweencomputers 112A-112C. When computer 112A is communicating with thenetwork 220, the SetLayerMetaData( ) method 580 communicates with thePropertyReplicator Class 450 on computers running geo-collaborationsoftware 130 which share the same virtual repository. For this example,the PropertyReplicator Class 450 executing on computer 112A communicatesthe selected layer's XML data with the PropertyReplicator Classesexecuting on computers 112B-112C, since the users of computers 112B and112C are members of the same virtual repository. The sequence of callsto RetrieveLayer( ) method 560, AddLayer( ) method 570, creates method575, LayerMetaDataXML( ) method 577, and SetLayerMetaData( ) method 580are made for each layer selected by the user.

If computer 112A is not communicating with network 220, thePropertyReplicator class 450 temporarily stores or buffers the selectedlayer's XML data until computer 112A begins communicating with network220. The PropertyReplicator class 450 transmits the buffered informationto collaboration software 140 once computer 112A communicates withnetwork 220. Alternatively, an additional computer may be used to act asa mailbox for offline users. In this alternative, the PropertyReplicatorclass 450 transmits the information to the additional computer so thatthe offline computer can retrieve the updates once it connects to thenetwork.

The SetLayerMetaData( ) method 580 asynchronously calls theSetLayerMetaData( ) method 590 on computers 112B and 112C to communicateXML data describing the selected layer. The SetLayerMetaData( ) method590 on computers 112A-112C updates the selected layer in XML format onthe respective machines. The SetLayerMetaData( ) method 590 on computers112A-112C communicate the XML data describing the selected layer withtheir respective map controllers by calling the SetLayerMetaData( )method 512 on the Map Controller class 420 on computers 112A-112C. TheMap Controller class 420 on each of computers 112A-112C determineswhether the selected layer is available and whether a layer filecorresponding to the XML data has been added to the map. If thecorresponding layer file is not available, the SetLayerMetaData( )method 512 does nothing. If the corresponding layer file is available,but has yet to be added to the map, the SetLayerMetaData( ) method 512adds the corresponding layer file to the map. If the corresponding layerfile has been added to the map, the SetLayerMetaData( ) method 512running on each computer updates the corresponding layer file with thereceived XML data by calling its respective SetLayerMetaData( ) method522 on itsr respective Map class 440. Once updated, map viewer 310 oncomputers 112A-112C will render the updated map on computers 112A-112C.

The methods 532, 542, 552, 553, and 562 of the sequence diagram 500describe an example of a user updating the contents of a particular maplayer. For example, a user of computer 112A wants to add his or herpersonal location to a map layer and have that personal location sharedwith users at computer 112B and 112C. Through the toolbar 320, the userinteracts with the map viewer 310 to have the UpdateLayerMetadata( )method 532 called on the user interface class 410. TheUpdateLayerMetadata( ) method 532 receives a command indicating whatcustomization a user wants to make to a map layer such as his or herlocation, a graphical incident, or the like. The UpdateLayerMetadata( )method 532 calls the GetLayerMetaData( ) method 542 on the MapController class 420. The GetLayerMetaData( ) method 542, in turn,retrieves layer metadata corresponding to the map layer the user wantsto customize by calling the GetLayerMetaData( ) method 552 on theMapLayer class 470. Once returned, the Map Controller 420 calls theEditMapLayerMetaData( ) method 553 on the User Interface class 410 toprovide the layer metadata to the User Interface class 410. The user ofcomputer 112A may add his or her personal location to the layermetadata. If the user is content with such changes, the updated layermetadata is sent to the PropertyReplicator class 450 by calling themethod SetLayerMetaData( ) method 562 to propagate the updated metadatato other users on computers 112A-112C as described in methods 590, 512,and 522 above.

The methods 572, 582, 592, 514, 534, 544, and 554 of the sequencediagram 500 describe an example of a user removing a layer from a map.For example, the user of computer 112A wants to remove a map layershowing his or her favorite bicycle training routes from being sharedwith the users at computer 112B-112C. The user selects the map layer heor she want removed from the toolbar 320 to have the RemoveMapLayer( )method 572 called on the User Interface class 410. The RemoveMapLayer( )method 572 calls the RemoveMapLayer( ) method 582 on the Map Controllerclass 420. The RemoveMapLayer( ) method 582 calls the RemoveLayer( )method 592 on the PropertyReplicator class 450 to remove the metadatacorresponding to the selected map layer from the PropertyReplicatorclass 450. The RemoveLayer( ) method 592 asynchronously calls theRemoveLayer( ) method 592 on PropertyReplicator classes being executedby computers 112A-112C. The asynchronous call typically includes amessage informing the computers 112A-112C that the selected layer is tobe removed from the map.

Methods 514, 524, 534, 544, and 554 are executed by thegeo-collaboration software 130 being executed on computers 112A-112C.The RemoveLayer( ) method 592 asynchronously receives the message andinforms the Map Controller class 420 by calling the RemoveLayer( )method 524. The RemoveLayer( ) method 524 calls the RemoveLayer( )method 534 on the Map class 440 to remove the select layer from the Mapclass 440. The RemoveLayer( ) method 534 calls the Delete( ) method 544on the MapLayer class 470 to delete the MapLayer instance correspondingto the selected layer. After deletion of the MapLayer instance,RemoveLayer( ) method 524 calls the Update( ) method 554 on the UserInterface class 410 in order for the map viewer 300 to render the mapwithout the selected layer.

FIG. 6 shows a calling sequence 600 illustrating the interaction of thesoftware objects of FIG. 4 for adding items such as a person's currentlocation, a line, an area, an object and the like to a map. Using thiscalling sequence 600, a user of geo-collaboration software 130 executingon computer 112A can add geo-spatial information such as a location of aperson, a point of interest, lines, roads, evacuation routes, no entryareas, risk areas, and the like and share this information with users ofcomputers 112B and 112C. Geo-spatial information is representedinternally to the geo-collaboration software 130 as a map item. To doso, the sequence of method calls 610, 620, 630, 640, 650, 660, 670, 680,690, 615, 625, 635, 645, and 655 are executed to create a MapIteminstance and share it with users on computers 112B and 112C. Forexample, the user selects from the toolbar 320 to have the Add( ) method610 called on the User Interface class 410. The Add( ) method 610 callsthe Add( ) method 620 on the Map Controller class 420 to specify acommand indicating that the type of item to be added to the map. TheAdd( ) method 620 calls the GetCurrentLocation( ) method 630 to obtain acurrent map location from the Map class 440. The current map location isthe last place the user clicked on the map such as map 330. This clickedposition is used as the center point for whatever type of object isbeing added to the map. The Add( ) method 620 then displays anappropriate editor for the type of item to be displayed to the user bycalling the DisplayEditUI( ) method 640. For example, a drawing editorwould be displayed if the user wants to specify a line or polygon to beadded to the map.

Once the user indicates he or she wants to save the newly created itemwith the display editor, the CreateMapItem( ) method 650 is called onthe Map Controller 420. The CreateMapItem( ) method 650, in turn, callsthe Create MapItem( ) method 660 on the Map class 440. The CreateMapItem( ) method 660, in turn, instantiates a MapItem class instance460 at time 670 and returns a unique identifier for the newly createMapItem instance at time 680. Upon receiving the unique identifier ofthe newly created MapItem, the CreateMapItem( ) method 650 retrieves theXML representation of the newly created MapItem by calling theGetMapItemXML( ) method 690 on the MapItem instance. The CreateMapItem() method 650 then informs the PropertyReplicator 450 of the XMLrepresentation by calling SetMapItemXML( ) method 615. TheSetMapItemXML( ) method 615 updates the PropertyReplicator with thenewly created MapItem's XML representation and informs the otherPropertyReplicators being executed on computers 112B-112C byasynchronously calling SetMapItemXML( ) method 625.

Method calls 625, 635, 645, and 655 are executed by geo-collaborationsoftware 130 executing on computers 112B-112C. SetMapItemXML( ) method625 asynchronously receives the MapItem's XML representation andsubsequently calls the SetMapItem( ) method 635 on the Map Controllerclass 420. The SetMapItem( ) method 635 calls the MapItem class 460 todraw the MapItem instance on the map according to the XML representationreceived. If the MapItem previously existed, it is redrawn according tothe received XML representation. For completeness, the SetMapItem( )method 635 calls the Update( ) method 655 to update the User Interfaceclass 410 with non-Map portions of the new MapItem details. For example,if there is a lot of text such as a long address associated with alocation, the location may be indicated with a graphic on the map andthe text may be displayed in the map item pane 340.

Method calls 665, 675, 685, 695, 612, 622, and 632 are executed bygeo-collaboration software 130 on computer 112A when, for example, auser wants to edit an existing map item. To do so, the user indicatesthe map item he or she wants to edit by selecting it from the displayedmap and making a selection which results in invoking the Edit( ) method665 on the User Interface class 410. The Edit( ) method 665 calls theEdit( ) method 675 on the Map Controller class 420. The Edit( ) method675 retrieves the corresponding MapItem instance by calling theGetSelected( ) method 685 on the Map class 440. At time 695, theselected MapItem instance is returned to the Map Controller class 420.Based on the type of the selected MapItem instance, the Edit( ) method675 invokes an appropriate editor for editing the selected map item bycalling the DisplayEditUI( ) method 612. The Edit( ) method 665 nowretrieves the XML representation of the selected map item by calling theGetMapItemXML( ) method 622 on the Map Item class 460. After retrievingthe corresponding XML representation, the SetMapItemXML( ) method 632 iscalled on the PropertyReplicator class 450 to update theProperReplicator class 450 and inform the ProperReplicator classesexecuting on computers 112B-112C. The sequence of method calls 625, 635,645, and 655 are performed as described above to replicate the XMLrepresentation of the edited map item and to render the updated map itemon computers 112A-112C.

The methods 642, 652, 662, 672, 682, 683, 692, 617, 627, and 637 of thesequence diagram 600 describe the interaction of software classes 410,420, 440, 450, and 460 when a user want to delete a map item. Forexample when a meeting is cancelled, the user of computer 112A wants toremove the map item for a meeting location where the users of computers112A-112C were planning to meet. The user indicates that he or she wantsto delete the map item by selecting it on the map displayed by mapviewer 300 and choosing a delete command accessible through the toolbar320. The Delete( ) method 642 is then called on the User Interface class410. The Delete( ) method 642, in turn, calls the Delete( ) method 652on the Map Controller 420 to indicate to the Map Controller that thecorresponding MapItem instance is to be deleted. The Delete( ) method652 calls the GetSelected( ) method 662 to retrieve the MapItem instancecorresponding to the selection made by the user on the User Interfaceclass 410. At time 672, the uniform resource locator (URL) for theselected MapItem instance is returned to the Map Controller class 420.The Delete( ) method 652 calls the DeleteMapItem( ) method 682 on thePropertyReplicator class 450 to remove the URL of the selected MapIteminstance from the PropertyReplicator class 450 and thePropertyReplicator classes being executed on computers 112B-112C. TheDeleteMapItem( ) method 682 asynchronously calls the PropertyReplicatorclasses on computers 112B-C.

The methods 683, 692, 617, 627, and 637 are executed bygeo-collaboration software 130 which is run on computers 112A-112C.DeleteMapItem( ) method 683 asynchronously receives notificationcontaining the URL of a map item that needs to be deleted and calls theDeleteMapItem( ) method 692 on the Map Controller class 420. TheDeleteMapItem( ) method 692 calls the Delete( ) method 617 on the Mapclass 440 with the URL corresponding to the MapItem instance to bedeleted. The Delete( ) method 617 removes the association of the URLwith the MapItem instance. The Delete( ) method 617 deletes the MapIteminstance from memory by calling the Delete( ) method 627. TheDeleteMapItem( ) method 692 then removes the selected map item from thebeing rendered by the map viewer 310 by calling Update( ) method 637 onthe User Interface class 410.

FIG. 7 shows a block diagram 700 of a portion of geo-collaborationsoftware which addresses co-navigating a map as illustrated in FIGS.3E-3G shared between computers in accordance with the present invention.It should be noted that co-navigating between two or more computerspresumes that the users of the two or more computers share or aremembers of the same virtual repository. The block diagram 700 showssoftware classes 710-770 which, when instantiated, interact which eachother to accomplish co-navigation between two or more computers. Theuser interface (UI) class 710 is the main user interface class whosemethods are accessed by a user through co-navigate pane 360. TheUserEndPoint class 720 identifies a unique combination of computers andusers. Each user can have UserEndPoints on a number of computers andeach computer can have UserEndPoints for a number of users. For example,the same user may operate two computers, a laptop and a workstation. OneUserEndPoint instance would uniquely identify the user operating thelaptop and another UserEndPoint instance would uniquely identify theuser operating the workstation. The Map class 730 is responsible forrendering a map image to a computer screen. The position orientationzoom (POZ) class 740 preferably contains a minimum set of fields todescribe a map perspective currently being rendered. For example, a POZinstance would contain information including a scale factor that mapdata is currently being rendered, the X and Y coordinates of the centerof the rendered map image, the amount of rotation of the map image aboutthe X and Y axes, the width of the rendered map image, and the height ofthe rendered map image. The NavigationController class 750 isresponsible for coordinating the interaction between the other softwarecomponents responsible for achieving co-navigation. In addition toPropertyReplicator class 450, PropertyReplicator class 760 is alsoresponsible for asynchronously propagating a POZ instance to othercomputers executing geo-collaboration software 130. The TimerGate class770 is responsible for making sure that followers are not swamped withPOZ instances which do not contribute to effective co-navigation. TheTimerGate class 770 regulates POZ instance traffic by sending onlymessages containing a POZ instance that differ from the previously sentmessage and by sending messages only as frequently as the user acting asa leader is specified. The operations of these classes will be furtherdescribed in connection with FIG. 8.

FIG. 8 shows a calling sequence 800 illustrating the interactions of thesoftware class instances of FIG. 7 in order to co-navigate a map betweentwo or more computers. The sequence of calls 810, 820, 830, 840, 850,and 860 are performed by geo-collaboration software 130 executed by acomputer whose user wants to act as a leader in a co-navigation session.

To initiate a co-navigation session, the user such as the utilitymanager responsible for the entire state of Louisiana selects the Leadbutton 363 in co-navigate pane 360 which results in calling the Lead( )method 810 on the UI class 710. The Lead( ) method 810 calls the Lead( )method 820 on the NavigationController class 750 to initiate aco-navigation session. The Lead( ) method 820 calls the GetPOZ( ) method830 to request a POZ instance for the current view of the Map 730. Attime 840, the POZ instance for the Map 730 is returned. The Lead( )method 820 then calls the SetPOZ( ) method 850 on the TimerGate class770. The SetPOZ( ) method 850 passes the POZ information to theTimerGate class 770 and decides whether a predetermined amount of timehas passed since sending the last POZ information before forwarding iton. A user may adjust the predetermined amount of time to send POZinformation by adjusting the slide bar 366 of the co-navigate pane 360.

After the predetermined amount of time has passed, the SetPOZ( ) method850 calls the SetPOZ( ) method 860 on the PropertyReplicator class 760.In response to either a local SetPOZ( ) method 860 call or one receivedasynchronously from a user running geo-collaboration software 130 onanother computer, the OnSetPOZ( ) method 870 is called. It should benoted that the PropertyReplicator class 760 interfaces withcollaboration software 140 to send and retrieve information of thenetwork 220.

The OnSetPOZ( ) method 870 is called for all participants including aleader and followers in the co-navigation. A sequence of calls 870, 880,890, and 815 to update the current view perspective is executed ingeo-collaborative software 130 running in each of the user's computerparticipating in the co-navigation session. The sequence of calls 870,880, 890, and 815 would be invoked on the leader of the co-navigationand one or more followers of the co-navigation. The OnSetPOZ( ) method870 calls the SetPOZ( ) method 880 on the NavigationController 750 oneach of the participants' computers. The SetPOZ( ) method 880 calls theSetPOZ( ) method 890 on the Map instance 730 on each of theparticipants' computers. The SetPOZ( ) method 890 instructs the Mapinstance 730 on each of the participants' computers to focus upon theplace specified in the POZ information carried in the POZ instance. TheSetPOZ( ) method 880 also calls the ShowPOZ( ) method 815 on the UIclass 710. The ShowPOZ( ) method 815 instructs the user interface todisplay the relevant parts of the map as defined by the POZ information.

The sequence of calls 825, 835, 845, 855, and 865 are executed by a userof geo-collaboration software 130 who wants to act as a follower in aco-navigation. To participate as a follower in a co-navigation session,a user, such as the relief manager responsible New Orleans, selects theFollow button 364 in co-navigate pane 360 which results in calling theFollow( ) method 825 on the UI class 710. The Follow( ) method 825 callsthe SetFollow( ) method 835 on the NavigationController class 750 toinform the NavigationController class 750 of the UserEndPoint instance720 specifying the user requesting to be a follower. The SetFollow( )method 835 calls the SetFollow( ) method 845 on the PropertyReplicatorclass 760 to instruct the PropertyReplicator class 760 to advise theleader of this user's interest in following the co-navigation session.The UserEndPoint instance 720 is passed asynchronously throughcollaboration software 140 to the PropertyReplicator class 760 beingexecuted on the computer whose user is acting as the leader to registerthe user's interest with the leader's PropertReplicator class 760.

The calling sequence of calls 855 and 865 is executed bygeo-collaboration software 130 executing on the leader's computer. Themethod OnAddFollower( ) 855 asynchronously receives the user's interestin following the co-navigation session by receiving its UserEndpointinstance. The method OnAddFollower( ) 855 calls the AddFollower( )method 865 on the NavigationController class 750 to register theUserEndpoint instance with the leader's NavigationController class byadding the UserEndpoint instance to the list of followers participatingin the co-navigation session. The method OnAddFollower( ) 855 provides amechanism for the leader of a co-navigation session to maintain a listof followers.

The sequence of calls 875, 885, and 895 is executed by a user ofgeo-collaboration software 130 who wants to stop acting as a follower ina co-navigation session. The sequence of calls 812 and 822 is executedby a user of geo-collaboration software 130 who is leading theco-navigation session.

To stop participation, the user such as the relief manager responsibleNew Orleans selects the Neither button 365 in co-navigate pane 360 whichresults in calling the Stop( ) method 875 on the UI class 710. The Stop() method 875 calls the SetFollow( ) method 885 on theNavigationController class 750 with the UserEndPoint instance indicatingthe unique reference of this user. The SetFollow( ) method 885 calls theRemoveFollower( ) method 895 on the ProperReplicator class 760. TheRemoveFollower( ) method 895 asynchronously passes the UserEndpointinstance of the follow to notify the geo-collaboration software 130executing on the leader's computer that the follower is no longerinterested in following the co-navigation session.

On the geo-collaboration software 130 executing on the leader'scomputer, the OnRemoveFollower( ) method 812 asynchronously receives theUserEndpoint instance of the follower. The OnRemoveFollower( ) method812 calls the RemoveFollower( ) method 822 on the NavigationControllerclass 750 to remove the UserEndpoint instance from the list ofUserEndpoints participating in the co-navigation session.

Alternatively, rather than registering UserEndPoint instances of memberswho want to follow the navigation of the map and calling the SetPOZ( )method 880 on the NavigationController 750 on each of the participants'computers, the leader's computer may broadcast messages containing POZinformation to members of the shared virtual space regardless of theirinterest or online/offline status and they can then choose whether ornot to follow the perspective of the leader.

FIG. 9 shows a block diagram 900 of a portion of geo-collaborationsoftware 130 which addresses location awareness as illustrated in FIGS.3K-3L on a map shared between two or more computers in accordance withthe present invention. It should be noted that location awareness of apoint of interest on a shared map between two or more computers presumesthat the users of the two or more computers share or are members of thesame virtual repository.

The block diagram 900 shows software classes 910-990 which, wheninstantiated, interact with each other to accomplish location awarenesson a map shared between two or more computers. The GPSPulser class 970is responsible for taking messages passed from the LocationAwarenessclass 910 and determining whether they should be passed out to thePropertyReplicator class 980 based on filter variables including timesince the last location was broadcasted, frequency with which the userhas chosen to broadcast their location, and whether the longitude,latitude, and altitude have changed. The LocationAwareness class 910coordinates the other software classes of this portion of thegeo-collaboration software 130. The LocationAwareness class 910 isresponsible for processing commands directly from a user or indirectlythrough a map, responding to updates to location and time from a globalpositioning system (GPS), creating and updating the current userslocation information data, activating or deactivating GPSPulser class970, sending location information for a user or device to aPropertyReplicator class 980, asynchronously receiving the locationinformation of other people or devices from the PropertyReplicator class980, and reading physical address information from a vCard or otherrepository for physical address information.

The Map class 960 is responsible for rendering the map image to thecomputer screen and maintaining a view consistent with a current POZinstance. The GPS class 920 is responsible for interfacing with aphysical GPS unit connected to the computer. By way of example, theconnection can be in the form of a direct serial port connection, aBluetooth® connection or a universal serial bus (USB) connection. Itwill be recognized that other suitable connections may be employed. Inaddition to the roles described above concerning the PropertyReplicatorclasses 450 and 760, the PropertyReplicator class 980 is responsible forasynchronously propagating location information and POZ information toother members of a collaborative session. The LocationInfo class 990preferably contains a minimum amount of data to unambiguously identify aposition of a person or item and unambiguously identify when theposition of a person or item was obtained. Optionally, a LocationInfoinstance may provide one or more status values for a person or item. ALocationInfo instance may be encoded in XML or other suitable formats.An exemplary LocationInfo instance may include a user's identity, alongitude reading, a latitude reading, an altitude reading, the time atwhich the longitude, latitude and altitude readings were made (UTCTime),the name of the time zone in force when making the reading (TimeZone),and the time zone offset which is the difference between the UTCTime andthe TimeZone time.

A GeoLocationService service 930 which is external to geo-collaborationsoftware 130 is responsible for reading a physical address such as “15Main Street, Paduka, Tex., USA“ and returning the latitude and longitudereadings as well as a description for all address that match a givenone.

The geo-collaboration software 130 may retrieve location information byvarious means including a GPS system, using the last clicked entry on amap, or a vCard, for example. FIG. 10 shows a calling sequenceillustrating the interactions of the software class instances of FIG. 9for sharing a location retrieved from a GPS system of a person or itemon a map shared between two or more computers. The sequence of calls tomethods 1010, 1020, 1030, 1040, and 1050 describe how thegeo-collaboration software 130 establishes a session with a GPS system.The GPS session is initiated by a user clicking on the “Connect GPS“link 372 of the Team Location pane 370 resulting in a call to theUseGPSLocation( ) method 1010 on the LocationAwareness class 910. Bydoing so, the user makes a request for GPS coordinates and expresses thedesire to translate these coordinates into location information carriedin a POZ instance as described above. The POS instance would then beshared between geo-collaboration software 130 executing on computers byusers sharing the same virtual repository.

The UseGPSLocation( ) method 1010 creates an instance of a GPS class 920to connect to an external GPS system by calling the create( ) method1020 on the GPS class 920. During the instantiation process, the GPSinstance calls the connect( ) method 1040 to cycle through serial postsincluding virtual serial posts such as USB ports and BlueToothconnections to look for a valid GPS data stream. The ShowConnectStatus() method 1050 is called to report the status of the cycled serial poststo the LocationAwareness class. If a valid GPS connection has been made,a GPS session is established between the geo-collaboration software 130and an external GPS system and that status is also reported.

The external GPS system communicates with the GPS class 920 by sendingan encoded stream of text which may suitably include longitude,latitude, altitude, current UTC time or other information. The GPS class920 filters and parses this stream and passes the resultant data to theLocation Awareness class 910 by calling SetLocation( ) method 1090. TheSetLocation( ) method 1090 stores information including the user'sidentity, status, latitude, longitude, altitude, and UTCTime in theLocationAwareness class 910.

The UseGPSLocation( ) method 1010 also creates an instance of a GPSPulser class 970 by calling Create( ) method 1030 on the GPS Pulserclass 970. After a predetermined time period ends which is denoted byTick( ) method 1060, the GPS Pulser class 970 notifies the LocationAwareness class 910 to send the most recent GPS reading through thePropertyReplicator 980. The GPS Pulser class 970 calls the Pulse( )method 1070 on the LocationAwareness class 910. The Pulse( ) method 1070then reports the current location information stored in theLocationAwareness class 910 by calling the SetLocation( ) method 1080 onthe PropertyReplicator class 980. The predetermined time period may beadjusted by a user to establish how frequently the system is to transmitthe user's location. This adjustment can be made by a pick list ofvalues or by entering a numeric value of minutes or seconds. When a usermakes such an adjustment, the SetPulseRate( ) method 1015 is called onthe GPS Pulser class 970.

The SetLocation( ) method 1080 stores the location information of theuser in memory or a persistent data store if the user's computer istemporarily not communicating with network 220. The location informationmay be stored as XML fragments, a serialized object, a structured querylanguage (SQL) entry, or the like.

The Transmit( ) method 1025 of the PropertyReplicator class 980 runs inits own thread. If the user's computer is communicating with the network220, the Transmit( ) method 1025 asynchronously sends the locationinformation of the user to all other members sharing the same virtualrepository in a scheduled manner. The PropertyReplicator classes on thisuser's computer and other computers of users utilizing the same virtualrepository will receive the location information of this user and willcall the SetLocation( ) method 1045 on their respectiveLocationAwareness classes 910. The SetLocation( ) method 1045 willupdate the set of tracked locations for team members having suppliedlocation information. SetLocation( ) method 1045 for each of the usersutilizing the same virtual repository calls the ShowLocation( ) method1055 on its respective Map class 960 to show the location informationreceived by its PropertyReplicator class 980. Optionally, thegeo-collaboration software 130 may show a ‘breadcrumb’ trail that showshow the user's location has changed over time.

A user may stop the GPS tracking of himself or herself by clicking onthe “Disconnect“ link 374 in the Team Location pane 370. When doing so,the Stop( ) method 1035 is called on the GPS Pulser class 970 whichceases notifying the LocationAwareness class 910 of GPS locationchanges. Consequently, GPS location updates will no longer be renderedto the user's map or the maps viewed by other team members.

FIG. 11 is a flow chart of a method 1100 for synchronizing map layersbetween two or more computers according to the present invention. Atstep 1110, a virtual repository is shared between two or more users. Atstep 1120, a map layer for adding data to a map object is created. Atstep 1130, the map layer is added to the map object. At step 1135, datadescribing the newly added map layer is retrieved.

At step 1140, the method determines whether there are other membersutilizing the same shared virtual repository. If there are, the methodproceeds to step 1160. At step 1160, data describing the added map layerare sent to the other members currently sharing the shared virtualrepository. Optionally at step 1160, if the computer of the user who isadding the new map layer is disconnected from a network, the datadescribing the added map layer is locally stored until the computer isreconnected to the network. At such time, the data is then sent to theother members of the virtual repository. At step 1170, at the othermembers' computers, data describing the added map layer is received andused to construct the added map layer. If the computer of the user whois adding the new map layer and one or more of the other members of thevirtual repository are connected to the network, the added map layer isthen rendered at the other members computers in real time. Otherwise,the added map layer is rendered at the time one or more of the othermembers connect to the network.

Returning to step 1140, if there are no other members utilizing the sameshared virtual repository, method 1100 proceeds to step 1150. At step1150, the data describing the added map layer is stored into a datarepository outside of the shared virtual repository.

FIG. 12 is a flow chart of a method 1200 for sharing a map item betweentwo or more computers according to the present invention. At step 1210,a map item for a map being rendered at a first member of a virtualrepository is created. For example, a user may use the Add feature oftoolbar 320 to add a map item. At step 1220, the map item is added tothe map file of the first member. At step 1230, data describingattributes of the map item is determined. For example, attributes mayinclude the font size, font style, the color, and shape of the map item.At step 1240, the data describing attributes of the map item isdistributed to one or more other members of the virtual repository. Atstep 1250, at the one or more other member's computers, data describingattributes of the map item is received. At step 1260, at the one or moreother member's computers, a map item corresponding to the received datais reconstructed. At step 1265, at the one or more other member'scomputers, the reconstructed map item is aggregated with a map file. Atstep 1270, the aggregated map file including the reconstructed map itemis automatically rendered at the one or more other member's computers atsubstantially the same time as the rendered map item on the firstmember's computer.

FIG. 13 is a flow chart of a method 1300 for co-navigating a map betweentwo or more computers according to the present invention. At step 1310,users of two or more computers are members of a common virtualrepository. At step 1320, a co-navigation mode is selected by one of themembers. At step 1330, the method 1300 determines if a leaderco-navigation mode has been selected for the user. If it has, the method1300 proceeds to step 1340. At step 1340, the parameters indicating thecurrent map perspective being rendered at the leader's computer is sentto other members of the common virtual repository. At step 1350, theleader may reposition his or her rendered map according to the desiresof the leader to establish a new map perspective. Once a new mapperspective is established, the method proceeds back to step 1340.

Returning to step 1330, if the selected co-navigation mode is not aleader, the method proceeds to step 1360. At step 1360, the method 1300determines if a follower co-navigation mode has been selected for theuser. If it has, the method 1300 proceeds to step 1370. At step 1370,parameters indicating the map perspective of the leader at step 1340 arereceived at the follower's computer. At step 1380, the follower's mapperspective is repositioned and automatically rendered at substantiallythe same time to match the leaders map perspective.

Returning to step 1360, if the follower co-navigation mode is notselected, the method proceeds to step 1390. At step 1390, the user haschosen not to participate in the co-navigation session and, thus, is incontrol of its own map perspective without affecting other members ofthe common virtual repository. Consequently, the follower's mapperspective is repositioned outside of a co-navigation session.

FIG. 14 is a flow chart of a method 1400 for plotting and sharing thelocation of a member between two or more other members of a commonvirtual repository in accordance with the present invention. At step1410, users of two or more computers are members of a common virtualrepository. At step 1420, a location determination technique for onemember of the common virtual repository is selected. The one member mayselect either inputting an address as defined in steps 1430, 1440, 1450,and 1460, utilizing a GPS as defined in steps 1470, 1472, 1474, and1476, or pointing to a geographical location on a map step 1480. SeeFIG. 3K for the look up address pop-up screen 334.

If an inputting address location technique is selected, the method 1400proceeds to step 1430. At step 1430, the method 1400 determines if avCard address is to be used. If it is, method 1400 proceeds to step 1440where a vCard address is selected as an inputted address. If the vCardaddress is not to be used, the method 1400 proceeds to step 1450 wherethe inputted address is typed. A portion of a postal address identifyinga location would suffice such as a street intersection of a city, astreet address and a city, or the like. Both steps 1440 and 1450 proceedto step 1460 where a geographical location based on the inputted addressis retrieved. Step 1460 may be implemented by an external web service,for example. At step 1485, a map item according to the retrievedgeographical location is created and shared according to the steps ofFIG. 12.

Returning to step 1420, if a GPS technique is selected at step 1420, themethod proceeds to step 1470. At step 1470, communication (COM) portsfor a GPS device are searched. At step 1472, a GPS device is connected.At optional step 1474, a broadcasting interval is selected to specifyhow frequently a geographical location is to be retrieved from the GPSdevice. At step 1476, a geographical location is retrieved from the GPSdevice. The method 1400 proceeds to step 1485 where a map item accordingto the retrieved location is created following the steps of FIG. 12.

Returning to step 1420, if a point and click technique is selected,method 1400 proceeds to step 1480. At step 1480, a geographical locationis retrieved by the one member of the common virtual repository pointingand clicking on a point on a rendered map. The method 1400 proceeds tostep 1485 where a map item according to the retrieved location iscreated following the steps of FIG. 12.

While the present invention is disclosed in the context of specificexemplary applications of specific exemplary software functions, manyvariations to these exemplary applications as well as the specificexemplary software functions are contemplated. With regard to otherexemplary applications, geo-collaboration software 130 may be utilizedby school board members from their respective homes to share andupcoming school redistricting plan, by politicians from their respectivelocations to share the redrawing of voting districts, by a corporatesales team disbursed across a country to share market penetrationinformation in various regions, and many other examples where geospatialinformation can be advantageously shared utilizing the presentinvention.

Further, while the present invention has been disclosed in the contextof various aspects of presently preferred embodiments, it will berecognized that the invention may be suitably applied to otherenvironments consistent with the claims which follow.

1. A method of sharing a geographical location on a map between firstand second computers, the method comprising: retrieving the geographicallocation to the first computer; adding the geographical location to afirst map file having a plurality of layers, the first map file beingrendered at the first computer; sending the geographical location to thesecond computer; aggregating the geographical location into a second mapfile at the second computer; and rendering the second map file includingthe geographical location at the second computer.
 2. The method of claim1 wherein first and second computers are simultaneously connected toeach other over a network, the method further comprising: displaying, atsubstantially the same time, the geographical location with first andsecond map files at first and second computers.
 3. The method of claim 1wherein the step of retrieving the geographical location includespointing and clicking at a location on the first map file being renderedat the first computer.
 4. The method of claim 1 wherein the step ofretrieving the geographical location includes typing in a portion of apostal address.
 5. The method of claim 1 wherein the step of retrievingthe geographical location includes retrieving the geographical locationfrom a global positioning system (GPS) device.
 6. The method of claim 1wherein the step of retrieving the geographical location occurs beforethe second computer connects to a network and the step of rendering thegeographical location occur after the second computer connects to thenetwork.
 7. The method of claim 1 wherein one layer of the plurality oflayers of the first map file is synchronized with a layer of the secondmap file.
 8. A computer readable medium whose contents cause a firstcomputer to share a geographical location on a map with a secondcomputer, by performing the steps of: retrieving the geographicallocation to the first computer; adding the geographical location to afirst map file having a plurality of layers, the first map file beingrendered at the first computer; sending the geographical location to thesecond computer; aggregating the geographical location into a second mapfile at the second computer; and rendering the second map file includingthe geographical location at the second computer.
 9. The computerreadable medium of claim 8 wherein first and second computers aresimultaneously connected to each other over a network, the methodfurther comprising: displaying, at substantially the same time, thegeographical location with first and second map files at first andsecond computers.
 10. The computer readable medium of claim 8 whereinthe step of retrieving the geographical location includes pointing andclicking at a location on the first map file being rendered at the firstcomputer.
 11. The computer readable medium of claim 8 wherein the stepof retrieving the geographical location includes typing in a portion ofa postal address.
 12. The computer readable medium of claim 8 whereinthe step of retrieving the geographical location includes retrieving thegeographical location from a global positioning system (GPS) device. 13.The computer readable medium of claim 8 wherein the step of retrievingthe geographical location occurs before the second computer connects toa network and the step of rendering the geographical location occurafter the second computer connects to the network.
 14. A method forco-navigating a map between first and second computers, comprising:displaying a first map file having a plurality of layers from a mapperspective at the first computer, the map perspective describingposition, orientation and zoom level of the displayed first map file;sending the map perspective being displayed at the first computer to thesecond computer; and rendering, at the second computer, a second mapfile from the same map perspective being displayed at the firstcomputer.
 15. The method of claim 14 further comprising: assigning thefirst computer to act as a leader; and assigning the second computer toact as a follower.
 16. The method of claim 14 further comprising:repositioning the displayed first map file at the first computer toestablish a second map perspective.
 17. The method of claim 14 whereinthe map perspective includes at least one of a scale factor of thedisplayed first map file, X and Y coordinates of the center of thedisplayed first map file, an amount of rotation of the displayed firstmap file about the X and Y axes, a width of the displayed first mapfile, and a height of the displayed first map file.
 18. The method ofclaim 14 wherein one layer of the plurality of layers of the first mapfile is synchronized with a layer of the second map file.
 19. A computerreadable medium whose contents cause a first computer to lead aco-navigation session of a map with a second computer, by performing thesteps of: displaying a first map file having a plurality of layers froma map perspective at the first computer, the map perspective describingposition, orientation and zoom level of the displayed first map file;sending the map perspective being displayed at the first computer to thesecond computer; and rendering, at the second computer, a second mapfile from the same map perspective being displayed at the firstcomputer.
 20. The computer readable medium of claim 19 furthercomprising: assigning the first computer to act as a leader; andassigning the second computer to act as a follower.
 21. The computerreadable medium of claim 19 further comprising: repositioning thedisplayed first map file at the first computer to establish a second mapperspective.
 22. The computer readable medium of claim 19 wherein themap perspective includes at least one of a scale factor of the displayedfirst map file, X and Y coordinates of the center of the displayed firstmap file, an amount of rotation of the displayed first map file aboutthe X and Y axes, a width of the displayed first map file, and a heightof the displayed first map file.